Conveyer system for heat treatment



July 14, 1959 o. HAUGwlTz coNvEYER SYSTEM FOR HEAT TREATMENT 2 Sheets-Sheet 1 Filed Dec. 13, 1957 O. HAU GWITZ CONVEYER SYSTEM F'OR HEAT TREATMENT July 14, 1959 2 Sheets-Sheet 2 Filed Dec. 1s, 1957 United States Patent O CONVEYER SYSTEM FOR HEAT TREATMENT Otto Haugwitz, La Celle Saint Cloud, France, assigner to Socit Anonyme Geolfroy-Delore, Paris, France, a French company Application December 13, 1957, Serial No. 702,704

Claims priority, application France December 15, 1956 3 Claims. (Cl. 263-6) This invention relates to conveyer systems especially applicable in connection with installation for the continuous hea-t treatment of lightweight metal articles, such as wire, light strip, metal strip', and the like.

A broad object of the invention is the provision of an improved conveyer system. Another object of the invention is to provide an improved heat treatment system specially advantageous for high-temperature treatment of metal articles having a relatively low heat capacity. Another object is to provide such a system wherein heat losses due to the conveyer part of the system will be greatly reduced. A more specic object is to provide a continuous conveyer means for putting a plurality of articles through a heating zone, wherein a predetermined section of the conveyer will remain permanently within the heating zone so that the same portion of the conveyer will remain directly exposed to heat throughout the process, thereby to eliminate substantially all heat losses from said zone other than the heat losses due to the thermal conductivity of the conveyer. Further objects will appear as the disclosure proceeds.

According to one aspect of the invention 'an improved conveyer system comprises at least two sets of longitudinal bar elements supported with the bars of the sets in yinternesting relation, means for imparting to the sets separate cyclic motions whereby all the bars in each set describe bodily displacements along generally elliptical paths in the vertical longitudinal planes of the bars, the cyclic displacements imparted to the respective sets being relatively displaced in time, so as to walk articles deposited on the supporting surface defined by the bars, over said surface.

In one embodiment the bars in each of two sets are all made to reciprocate longitudinally to provide a horizontal component for said elliptical displacement, and means are further provided for guiding the bars along a vertical component of said displacement, in such a manner that at the start of each reciprocation one set of bars is brought to a highermost position while the other set is brought to a lowermost position of its vertical displacement component. That Iset of bars which is uppermost during the forward portion of a displacement cycle serves to advance the articles to be treated while the other set of bars is accomplishing its return movement in a lowermost position below the level of the supporting surface. Thereafter the second set of bars assumes an uppermost portion while the lirst set is lowered, and the articles are now taken up by the second set and advanced a further step, and so on repeatedly. The articles are alternately advanced by the two sets of bars and progress smoothly ata substantially uniform rate without being subjected to shocks.

Preferably the operating mechanism yincluding such components as linkages, cans, rollers and the like, is entirely positioned outside of the heating zone of the installation.

The bars in each set may be straight or they may be ICC made arcuate, if it be desired for example that the input and output stations for the articles should be provided at elevations lower than the heating enclosure. In this latter case the conveyer may be surrounded by a tunnel having its ends dipping into Water tanks, in order to seal the atmosphere within the heating zone or furnace and thereby make it possible to control said atmosphere.

An embodiment of the invention will now be described as applied by way of example to an installation for annealing steel wire. Figs. 1 and 2 of the accompanying drawings illustrate the system in elevation and in overhead plan view respectively.

By way of further example the system is shown as combined with the improved wire handling system disclosed in my copending patent application Serial No. 702,644, filed December 13, 1957, to which reference may consequently be made yfor a fuller disclosure of the means shown herein for feeding the wire in displaced overlapping loops at the input end of the conveyer, and lifting the loops oil the conveyer at the output end thereof.

Referring to the accompanying drawings, wire 1 to be annealed is continuously fed at a high rate to a feedout head 2 which casts olf the wire at its base in successive circular loops. The loops are deposited on the surface of a conveyer 3 comprising three belts stretched across sheaves 4. The conveyer 3 is immersed in a water tank 5. The array 6 of overlapping loops is then Itransferred from the conveyer 3 to the surface of a conveyer generally designated 7 and constructed in accordance with the present `invention as will be more fully described hereinafter. The array off loops 6 is advanced over the conveyer 7 through an annealing furnace 8 and is then fed downward into another water tank 9. A tunnel 10 is connected to each end of the furnace and its end sections are immersed in the respective water tanks 5 and 9 to seal the interior of the furnace from the outer atmosphere and permit the furnace atmosphere to be controlled as to its chemical composition and pressure conditions. The wire 6 is transferred within tank 9 to another conveyer 11 comprising three belts applied against a sheave 12 by presser pulleys 13. A belt 14 is further trained between the sheave 12 yand a guide pulley 15. In this way the wire 6 is gripped between the belts 11 and 14 and turned upside down without the overlapping loops of wire being disturbed. The wire is then taken up by being lifted oi the belt 14, a conventional taper casing 16 being provided to prevent the wire from ballooning out, and a retarding or tensioning device 17 is provided. The wire may be finally delivered into cylinders 18 rotated at the same speed as the feedout head 2, the rotations being synchronized through the belt drive 19.

The novel conveyer 7 essentially comprises two sets of bars 20 and 21 in the form of vertical, upwardly-convex circular arcs, the bars in each set being secured to one another in transversely spaced relation in any suitable manner, and the two sets being arranged so that the respective bars thereof alternate. All the bars extend through the annealing furnace shown at 8 which surrounds substantially an apical portion of 'the arcs. The bars have their opposite end portions projecting downwardly into the water tanks 5 `and 11 and into the spaces between the transversely spaced belts of each conveyers 3 and 11 respectively. All the bars of set 20 are interconnected at their respective ends by cross members 22, and all the bars 21 are similarly interconnected at their ends by cross members 23. A cross member 22 extends through apertures formed in the bars of set 21 and a cross member 23 extends through apertures in the bars of set 20. Corresponding ends of the pair` of cross members 22 are interconnected by raillike members 24 which are sangrar formed with the same curvature in a vertical plane as the bars, but extend alongside the furnace outwardly thereof instead of passing through the furnace. The rail members 24. are supported in their intermediate portions each by a pair of spaced rollers in the same way the corresponding ends of cross members 23 are interconnected by arcuate rail members extending alongside trie furnace and supported by the spaced rollers 27. The roll rs 25 and 27 are journalled o-n vertically reciprocable supports to be presently described.

Each of the rails 2li 25 has Secured to a point thereof intermediate the rollers or a generally radial arm Z3 or 29 which extends downwardly and las journalled to its lower end a follower roller and 3l; both rollers 3i? associated with rails with the periphery of a cam 32 and bot: sociated with rails cooperate with a. cam 33.

act on the lower extremities of the arms and 29 to press the rollers ebried thereby into hrm engagement with the surfaces of the respec inalled on sliding reciprocation relatively to stationary guide s ructure mounted on each. side of the furnace and including guide rollers engaging the vertical edges of the `plates rrly the rollers 27' supporting thc rails are journallci on er T which reciprocate vertically in gement w tn guide rollers 39, as will be apparent trom the drawings. Rollers dll and il journalled at the lower ends of an ls projecting do'-,vnwardly from the plates 36 and 37 and cooperate with the peripheries of respective cams Y ly with the cams 32 and 33 pre1 -n ion a transversely extending rotatable drive shaft driven in rotation from any suitable source.

it will be readily reciated that the two cams 32 and 4Z, or 33 and do, which respectively relate to each set of bars can be so shaped that continuous rotation of the shaft l-flwill impart to the rail members and associated set of bars a cyclic, generally elliptical movement in a vertical lane, the horizontal longitudinal component of such displacement being imparted by the cam 33 or acting on the radial arm or 29, and the vertical component of the displacement being imrted by the cam or i3 acing on the vertical plate or 37. Thus, any given po it o a particu itrrer set will describe small generally iipttcal path f a by way of exscribed by the Sim.

ample in dotted lines for the trajectory ss lember 23 at the left side of Wg.

Furthermore, the relative setting between the 2 and imparting motion to the bar structure and t"e cans 33 and imparting motion to the bar structure 2l, is such that the cycles of displacement of the two bar structures are time-displaced by one n Af a complete cycle. ln this way it will be unt erstood that the array 6 of loops of wire as deposited from the input conveyor belts 3 upon the inlet end ol the bar conveyer within tanlt 5, will be advanced by the alternate "wall:- ing motion of the two sets of bars into and through 'the annealing furnace 7 and out again into water tanlf. 9. There the annealed wire is transferred on to belt conveyer and passed around the sheave 12 to the r leaf of said belt co^veyer lil, whence the wire n a manner already described.

A ze of this invention is 'that the intermediate portion of the bar conveyer remains at all times within the furnace so that no heat is withdrawn from the furnace during an annealing operation by movement of the conveyer out of the furnace, as would Cil be the case with any of the various forms of conventional conveyers currently used in installations of the ltind described, wherein the conveyor itself must necessarily pass through the furnace together with the parts carried thereby7 and thus continually carries away valuable heat units as it passes out of the furnace. This waste of high-temperature energy is completely eliminated by the invention, and it is further noted that the intermediate section of the conveyer within the furnace preferably is insulated thermally from ythe outer sections. rl`he rate of advance imparted by the conveyer is readily adjustable e.g. by action on the cams,

Among the many modifications conceivable within the scope of this invention, i may mention that wherein there are provided more than two, e.g. three, sets of internested bars and the cyclic displacements imparted to the respective sets being displaced in time by a corresponding fraction, eg, 2/3, of a cycle.

at l claim is: ln a heat treating system in combination, at least wo bar assemblies each comprising a set of transversely paced bars having an arcuate configuration in a vertical lane with the apex of the arcs directed upward, means supporting said assemblies in parallel internested relation whereby all the bars define a generally part-cylindrical supporting surface having a substantially hat apical portion intermediate the ends of the assemblies and end portions drooping down from said flat apical portion towards the ends of the assemblies, liquid container means into which said drooping end portions project, tunnel-like extensions projecting from the ends of said enclosure into said container means in surrounding relation with said oar assemblies whereby to define a sealed ace within said enclosure and tunnel extensions, a ging station at an input end of said assemblies for cing articles to be treated on said supporting surface,

imparting to the respective assemblies time-displaced generally elliptical cyclic` motions in a vertical lane to advance said articles over said surface through said enclosure, and a discharging station at the opposite ,nd of the assemblies for removing the treated articles.

2. ln a system as claimed in claim l, guide rail means of generally similar arcuate conguration as said bars interconnecting the opposite ends of each of said bar assemblies and extending alongside said enclosure and tunnel-like extensions externally thereof, rollers supporting said guide rail means in intermediate portions thereof, vertically reciprocable supports on which said rollers are journalled, and cam means for reciprocating said supports and for simultaneously imparting to said guide rail means longitudinal reciprocations relatively to said rollers.

3. ln a system as claimed in claim l, an input belt conveyer in internested relation with the bar assemblies at an input end of said system arranged to transfer articles placed on said input conveyor to said supporting surface7 and an output belt conveyer in internested relation with the bar assemblies at the output end of the system arranged for transfer of treated articles from said supportinU surface to said output conveyer.

References Cited in the le of this patent UNlTED STATES PATENTS l,441,042 Thackray lan. 2, 1923 1,792,074- Cochran Feb. 10, 1931 2,039,203 Oglivy-W'ebb Apr. 28, 1936 FOREIGN PATENTS 291,580 Great Britain .lune 7, 1928 

